import axios, {
  AxiosRequestConfig,
  AxiosError,
  AxiosResponse,
  CancelToken,
} from "axios";
import { ElLoading, ElMessage } from "element-plus";
interface CustomOptions {
  repeat_request_cancel?: boolean;
  loading?: boolean;
  restore_data_format?: boolean;
  error_message_show?: boolean;
  code_message_show?: boolean;
}

interface LoadingOptions {
  fullscreen?: boolean;
  text?: string;
  customClass?: string;
  spinner?: string;
  background?: string;
}

const pendingMap: Map<string, CancelToken> = new Map();

interface LoadingInstance {
  _target: any;
  _count: number;
}

const LoadingInstance: LoadingInstance = {
  _target: null,
  _count: 0,
};

function Axios(
  axiosConfig: AxiosRequestConfig,
  customOptions: CustomOptions = {},
  loadingOptions: LoadingOptions = {},
) {
  const service = axios.create({
    baseURL: import.meta.env.VITE_API_BASE_URL,
    timeout: 1000 * 60,
    responseType: "json",
  });

  // 自定义配置
  const custom_options = Object.assign(
    {
      repeat_request_cancel: true, //阻止重复请求
      loading: false, //加载中
      restore_data_format: true,
      error_message_show: true, //处理错误状态码
      code_message_show: true, //错误code信息提示
    },
    customOptions,
  );

  // 请求拦截
  service.interceptors.request.use(
    (config: any) => {
      removePending(config);
      custom_options.repeat_request_cancel && addPending(config);
      // 创建loading实例
      if (custom_options.loading) {
        LoadingInstance._count++;
        if (LoadingInstance._count === 1) {
          LoadingInstance._target = ElLoading.service(loadingOptions);
        }
      }
      // 自动携带token
      // if (getToken() && typeof window !== "undefined") {
      //   config.headers.Authorization = getToken() as string;
      // }

      return config;
    },
    (error: AxiosError) => {
      return Promise.reject(error);
    },
  );

  // 响应拦截
  service.interceptors.response.use(
    (response: AxiosResponse) => {
      removePending(response.config);
      custom_options.loading && closeLoading(custom_options); // 关闭loading
      if (
        custom_options.code_message_show &&
        response.data &&
        response.data.code !== 200
      ) {
        ElMessage({
          type: "error",
          message: response.data.msg as string,
        });
        return Promise.reject(response.data); // code不等于200, 页面具体逻辑就不执行了
      }
      return custom_options.restore_data_format ? response.data : response;
    },
    (error: AxiosError) => {
      error.config && removePending(error.config);
      custom_options.loading && closeLoading(custom_options); // 关闭loading
      custom_options.error_message_show && httpErrorStatusHandle(error); // 处理错误状态码
      return Promise.reject(error); // 错误继续返回给到具体页面
    },
  );

  return service(axiosConfig);
}

export default Axios;

/**
 * 处理异常
 * @param {*} error
 */
function httpErrorStatusHandle(error: any) {
  // 处理被取消的请求
  if (axios.isCancel(error))
    return console.error("请求的重复请求：" + error.message);
  let message = "";
  if (error && error.response) {
    switch (error.response.status) {
      case 302:
        message = "接口重定向了！";
        break;
      case 400:
        message = "参数不正确！";
        break;
      case 401:
        message = "您未登录，或者登录已经超时，请先登录！";
        break;
      case 403:
        message = "您没有权限操作！";
        break;
      case 404:
        message = `请求地址出错: ${error.response.config.url}`;
        break; // 在正确域名下
      case 408:
        message = "请求超时！";
        break;
      case 409:
        message = "系统已存在相同数据！";
        break;
      case 500:
        message = "服务器内部错误！";
        break;
      case 501:
        message = "服务未实现！";
        break;
      case 502:
        message = "网关错误！";
        break;
      case 503:
        message = "服务不可用！";
        break;
      case 504:
        message = "服务暂时无法访问，请稍后再试！";
        break;
      case 505:
        message = "HTTP版本不受支持！";
        break;
      default:
        message = "异常问题，请联系管理员！";
        break;
    }
  }
  if (error.message.includes("timeout")) message = "网络请求超时！";
  if (error.message.includes("Network"))
    message = window.navigator.onLine ? "服务端异常！" : "您断网了！";

  ElMessage({
    type: "error",
    message,
  });
}

/**
 * 关闭Loading层实例
 * @param {*} _options
 */
function closeLoading(_options: CustomOptions) {
  if (_options.loading && LoadingInstance._count > 0) LoadingInstance._count--;
  if (LoadingInstance._count === 0) {
    LoadingInstance._target.close();
    LoadingInstance._target = null;
  }
}

/**
 * 储存每个请求的唯一cancel回调, 以此为标识
 * @param {*} config
 */
function addPending(config: AxiosRequestConfig) {
  const pendingKey = getPendingKey(config);
  config.cancelToken =
    config.cancelToken ||
    new axios.CancelToken((cancel: any) => {
      if (!pendingMap.has(pendingKey)) {
        pendingMap.set(pendingKey, cancel);
      }
    });
}

/**
 * 删除重复的请求
 * @param {*} config
 */
function removePending(config: AxiosRequestConfig) {
  const pendingKey = getPendingKey(config);
  if (pendingMap.has(pendingKey)) {
    const cancelToken: any = pendingMap.get(pendingKey);
    cancelToken(pendingKey);
    pendingMap.delete(pendingKey);
  }
}

/**
 * 生成唯一的每个请求的唯一key
 * @param {*} config
 * @returns
 */
function getPendingKey(config: AxiosRequestConfig) {
  const info: AxiosRequestConfig = config;
  if (typeof info.data === "string") info.data = JSON.parse(info.data); // response里面返回的config.data是个字符串对象
  return [
    info.url,
    info.method,
    JSON.stringify(info.params),
    JSON.stringify(info.data),
  ].join("&");
}
